Propellant polymeric compositions containing beryllium



United tates Fice 3,3d4,2l2 PR'UPELLANT PGLYMEREC OMPOSHTIUNS CQNTAHNENG IBERYLZLEUM Gaetano F. DAlelio, South Bend, Endh, assignor to Del Men Research Cm, Cleveland, @hio, a corporation of Delaware No Drawing. ontinuation of applications Ser. No. 751,567, July 28, 1953, Ser. No. 761,484, Sent. 17, 1958, and 762,227, Sept. 22, 1958. This application Sept. 27, 1961, Ser. No. 141,012

20 Claims. (Cl. 149-19) This invention relates to polymers containing beryllium. This application is a continuation of'applicants copending applications Serial Numbers 751,567, now abandoned, filed July 28, 1958; 761,484, now abandoned, filed September 17, 1958; and 762,227, now abandoned, filed September 22, 1958.

Because of the high energy content of such compounds, beryllium compounds having beryllium to carbon bonds, such as beryllium alkyls, should be useful as fuel compositions. However, because of their tendency to ignite spontaneously upon exposure to air, and the highly reactive nature of these compounds, the use of beryllium alltyls involves considerable danger and necessitates various precautionary steps. Moreover, since they are liquids, their use as propellant fuels for rockets, missiles, and related devices, has the drawback common to liquid fuels in that complicated containers and pumping devices are required, and the sloshing effect of the liquids in their containers causes shifting of weight which adversely affects directional control.

In accordance with the present invention, polymeric beryllium compounds have been discovered which have more easily controlled flammability and reactivity while still retaining high energy content. Such polymeric materials can be made in a solid state and thereby have the inherent advantages of solid fuels used for propelling purposes.

The polymeric compositions of this invention are prepared from beryllium hydrides, and hydrocarbon-substituted beryllium hydrides, by reaction with hydrocarbon compounds (including those having substituents thereon which are nonreactive to the beryllium hydrides and substituted hydrides), having a plurality of ethylenically unsaturated groups therein, or at least one acetylenic group therein, including polymers containing such groups.

Such compositions can be made in liquid or solid form, and can be converted to infusible forms. These polymeric compositions are useful as high energy fuels, either as a supplement or as a main component, and are particularly useful in the solid form for such purposes. Particularly useful infusible solid fuels can also be made by incorporating a solid or liquid oxidizing agent into the polymeric compositions of this invention while they are in a liquid or thermoplastic state, and then converting the polymer to a crosslinked, infusible condition.

Typical examples of the hydrides and hydrocarbon substituted hydrides of beryllium which can be used in the practice of this invention include, but are not limited to, the following: beryllium hydride, beryllium alkyl hydrides, such as methyl beryllium hydride, ethyl beryllium hydride, propyl beryllium hydride, hutyl beryllium hydride, octyl beryllium hydride, nonyl beryllium hydride, styryl beryllium hydride, cyclohexyl beryllium hydride, phenyl beryllium hydride, dimethyl beryllium, diethyl beryllium, methyl ethyl beryllium, dipropyl beryllium, dibutyl beryllium, ethyl butyl beryllium, diamyl beryllium, dioctyl beryllium, distyryl beryllium, methyl phenyl berylliurn, dicyclohexyl beryllium, ethyl cyclohexyl beryllium, dicyclopentyl beryllium, etc. These beryllium compounds, sometimes generally referred to hereinafter as beryllium hydride compounds, can be used as such or in various complex forms, such as complexes with ethers, tertiary amines, thioethers, etc.

It has been found, in accordance with this invention, that polyalkenyl or acetylenic compounds, such as butadiene, acetylene, etc., and the beryllium hydride compounds can be made to react in such a manner as to produce polymers having beryllium in the polymer chain, and in relatively high proportions. The lower limit on the proportions of polyalkenyl or acetylenic compound will vary according to its functionality. For example, the polymeric products can contain as little as 0.67 mole of dialltenyl or acetylenic compound per atom of beryllium, and as little as 0.33 mole of trialkenyl compound per atom of beryllium. While even more olefin can be used, depending on how low a percentage of beryllium is desired in the polymer, it is generally desirable to have no more than about 1.5 moles of polyalkenyl or acetylenic compound per atom of beryllium in the polymer. The range is advantageously between about 1 and 1.5 moles of polyalkenyl or acetylenic compound per atom of beryllium. On the basis of metal equivalents, the general range is translated to mean from less than about 0.5 mole to about 0.8 mole of unsaturated compound per equivalent of beryllium. However, when other metals are substituted in part for the beryllium, as indicated hereinafter, these proportions are modified accordingly.

The polymer compositions of this invention comprise 595 percent of an oxidizing agent of the type used in solid propellant fuel compositions, such as potassium perchlorate, or other solid inorganic oxidizing salt or an ArClO compound wherein Ar is a mononuclear hydrocarbon radical, and 95-5 percent of a polymer represented by the formula R-(BeY--),,BeR wherein R is hydrogen or hydrocarbon radical, preferably of no more than 24 carbon atoms, :1 is an integer having a value of at least 2, preferably at least 4, and Y is a polyvalent radical derived from the acetylenic and ethylenic compounds described herein, and having as many valencies as there are beryllium atoms attached thereto. The polymers used in making the fuel composition of this invention are described and claimed in applicants copending application Serial No. 141,013, filed the same date herewith.

When derived from a dialkenyl compound or from a monoacetylenic compound having no ethylenic groups therein, Y is a divalent radical. When derived from a monoacetylenic compound, which also has one ethylenic group therein, or from compounds having a plurality of acetylenic groups therein, or from compounds having more than two ethylenic groups therein, Y can have more than two valencies. When derived from a polymer having a considerable number of ethylenic or acetylenic groups therein, Y also has more than two valencies. The R hydrocarbon radical preferably has no more than 24 carbon atoms. A hydrocarbon nucleus of R can have attached thereto substituents which are non-reactive toward the metal compound used in the preparation of the polymer. Also additional unreacted ethylenic and acetylenic groups may also be present.

Polymers used in this invention have a plurality of repeating units therein, which can be represented by the formula -BeY- in which Y is a polyvalent hydrocarbon radical. Some of these polyvalent hydrocarbon radicals can be derived from a hydrocarbon compound having a plurality of ethylenic groups therein and having the formula wherein R represents hydrogen or a hydrocarbon group, and Z represents a single bond between the two carbon atoms adjacent to Z, or a polyvalent hydrocarbon group.

The hydrocarbon nucleus of R and of Z can have attached thereto substituents which are nonreactive toward the beryllium hydride compound used in the preparation of the polymer. -Iowever, acetylenic or additional ethylenic groups can also be attached to R and Z.

Certain polyvalent hydrocarbon radicals as represented by Y can also be derived from hydrocarbons having acetylenic or allenic unsaturation herein.

While it is believed that each beryllium atom becomes attached to one of the carbon atoms of an ethylenic or acetylenic group, it is also possible that the beryllium migrates during or after the reaction between the beryllium hydride compound and the polyalkenyl or acetylenic compound, and becomes attached to another carbon atom of the resultant compound that gives a more stable derivative. Thus, the beryllium may actually be attached to one of the R groups, or to Z. For that reason, Y groups derived from polyalkenyl compounds can be represented as a polyvalent radical having the formula in which the specific carbon atoms to which the beryllium is attached are not specified.

In polymers derived from polyalkenyl hydrocarbon compounds, Y can be replaced by the above formula in which the actual points of attachment of the beryllium are not pinpointed, as follows:

When the beryllium becomes attached and does not migrate from the ethylenic group, the polymeric product from polyalkenyl compounds can be represented by the following formula:

tanni or generally can be simplified, particularly where the ethylenic groups are vinyl or vinylidene groups, to:

Likewise, when the acetylenic compound is represented as RCECR, wherein R is hydrogen or a hydrocarbon group, the metal can actually be attached to one of the carbon atoms of the acetylenic group, or to the R group. For that reason, Y can be represented as a polyvalent radical having the formula R C H without pinpointing the carbon atom to which the metal is attached.

In accordance with the above discussions, typical Y groups derived from acetylenic or allenic compounds include, but are not restricted to, the following:

OH2HOH2C5II4CH2HCI'IF; etc. Accordingly, the polymeric products of this invention derived from acetylenic compounds can be represented by the formula:

R(BeC H R BeR When the beryllium becomes attached and does not migrate from the acetylenic group, the polymeric product is represented by the following formula:

R(BeRHCCHR) BeR In the above formula the various symbols are as previously defined and additional acetylenic or ethylenic groups can also be attached to one or more Rs.

Likewise, the polymeric products derived from allenic compounds are believed to be represented by the corresponding formulas:

respectively.

When the beryllium hydride compound has no more than one hydrocarbon group attached to each beryllium atom, such as beryllium hydride, ethyl beryllium hydride, methyl beryllium hydride, propyl beryllium hydride, styryl beryllium hydride, etc., and an acetylenic or allenic compound is used, it is believed that polymerization proceeds linearly, at least initially, as follows:

When a beryllium compound is used which has two hydrocarbon groups on each beryllium atom, the hydrocarbon groups can be displaced by the acetylenic or allenic compounds and the R groups liberated as the corresponding olefin. For example, when the two Rs on each beryllium atom are hydrocarbon groups, the polymer is believed to proceed linearly, at least initially, as follows:

In accordance with the preceding, the polymers of this invention have a plurality of repeating units therein of the formula BeY-. In these repeating units, Y is a polyvalent hydrocarbon radical as defined above. Specific Y radicals which fit this description appear in the following repeating formulas which represent the products and various examples described hereinafter. For example, in Example I, the polymers have a repeating unit structure Of -B6-C2H c H4C2H4--.

In Example IV, the product has a repeating unit structure of -Be-C H The pro-duct of Example V has a repeating unit structure of -Be-C H (CH In Example VI, the polymer resulting from reaction of diallyl benzene has a repeating unit structure of and the polymer resulting from reaction of divinyl naphthalene has a repeating unit structure of In Example VI, the polymer resulting from the reaction of divinyl diphenyl has a repeating unit structure of BCC2H4CGH4CSH4CZH4 In Example VII, the polymer resulting from the reaction of divinyl cyclohexane has a repeating unit structure of BeC H C H C H In Example Ia, HM and IVa, the resultant polymers have repeating unit structures of BeC H respectively.

Infusible polymers can be obtained in the practice of this invention by using a hydrocarbon compound having three or more ethylenic groups therein, or at least one acetylenic and one ethylenic group or a plurality of acetylenic groups therein, or by using, together with the beryllium hydride compound, a trivalent metal compound, such as the boron and aluminum hydrides and their hydrocarbon-substituted hydri-des. When the above-indicated types of unsaturated compounds are used, the crosslinking is effected through another Y group, which can also be represented by the various formulas indicated above for Y. When a trivalent metal compound is used, such as a boron or aluminum hydride, together with the beryllium hydride compound, the crosslinkage can also be represented as a Y group which will be connected between polymer molecules through the trivalent metal atoms.

Por example, when crosslinking is effected through a copolymerized trivalent metal atom such as aluminum, it is believed that the cross-linked portions of the polymer can be represented as In the polymerization described herein, when con-ditions permit, the hydrocarbon group which is replaced by the polyalkenyl or acetylenic compound, generally escapes from the system as an olefin. In cases of closed systems, the buildup of pressure, or the reluctance of a radical such as phenyl toward olefin formation, can result in the attachment of the hydrocarbon group to the carbon atom of the ethylenic or acetylenic group, other than the one to which the beryllium is attached.

Various modifications of polymeric materials can be made according to the practice of this invention by adjusting the proportions of reactants and the conditions under which the materials are made to react. For example, the amount of crosslinking is controlled by the amount of compound having three or more ethylenic groups, etc., therein that is added, or the amount of trivalent metal compound that is added for that purpose. The selectivity, type of reaction, and product, can be controlled somewhat by selecting appropriate beryllium compounds, con centration thereof, polyalkenyl or acetylenic compound, and also by the use of certain amounts of monoalkenyl compounds. For example, since the hydrogen in these beryllium compounds is generally more easily replaced than alkyl compounds, it is possible thereby to control somewhat the type and extent of reaction.

When it is desired to control the molecular weight of a linear polymer, or to put terminal carbon groups on a polymer chain, this can be accomplished by using a monoolefin, such as ethylene, together with the polyalkenyl (or acetylenic) compound. The latter can also be effected by using a monoor di-substituted beryllium, alone or together with unsubstituted beryllium hydride.

Some control over the type and extent of reaction can be effected by using beryllium hydride compounds having hydrocarbon groups of different sizes. It is sometimes desirable, also, that the hydrocarbon groups to be replaced by the polyalkenyl or acetylenic compound be of a smaller size than the polyalkenyl or acetylenic compound. This is particularly desirable where there is a displaced hydrocarbon group escaping as a byproduct olefin. In some cases, a polyalkenyl or acetylenic compound of higher boiling point than the resultant olefin permits escape of the olefin upon refluxing of the polyalkenyl or acetylenic compound, or upon maintaining the reaction temperature below that at which the polyalkenyl or acetylenic compound vaporizes to an undesirable extent. In some cases, particularly where the difference in volatility is not great, the olefin can be permitted to escape in a stream of the polyalkenyl or acetylenic compound passing through the system, or in a stream of inert gas with additional polyalkenyl or acetylenic com-pound being fed to the system. In cases where the polyalkenyl or acetylenic compound has a higher vapor pressure than any olefin that might be given off as a byproduct, a closed system can advantageously be used to favor the desired displacement.

The temperature conditions for the promotion of polymer formation, in accordance with the practice of this invention, vary in accordance with the reactivity of the re agents being used. When a beryllium hydride is being reacted with a polyalkenyl or acetylenic compound, a temperature in the range of 70-80 C. is generally suitable. When beryllium hydride compounds containing both hydrogen and hydrocarbon groups are used, the reaction can be controlled mainly to displace the hydrogen by keeping the temperature below 100 C. When hydrocarbon groups are to be displaced from a beryllium hydride compound, a temperature of about IOU-120 C. is preferred. Depending upon the decomposition temperatures of the particular reagent, and the polymeric product, it is generally advantageous not to exceed a temperature of about 140 C. When a mixture of a beryllium and a beryllium "hydride compound containing hydrocarbon groups is being used, it is generally desirable to maintain the appropriate temperature until most of the hydrogen has been displaced and then to raise the temperature to that more suitable for displacement of the hydrocarbon group. In some cases the temperature control can be facilitated by the use of an inert solvent, such as heptane, octane, benzene, toluene, xylene, etc., whose boiling point is close to the desired temperature.

The time required for polymer formation varies in accordance with the reactivity of the ethylenic or acetylenic groups in the polyalkenyl or acetylenic compound, the type of group to be displaced in the beryllium hydride compound, the temperature being used, and various other factors which favor the reaction, such as the use of metal catalysts, such as nickel, cobalt, etc., the removal of the byproduct olefin, etc. With respect to the last condition, an increase in concentration of such byproduct olefin promotes an equilibrium which completes with the progress of the polymer formation. Therefore, unless the olefin is permitted to escape, or it is absorbed by addition, this tends to slow down the polymerization. The polymerization proceeds most rapidly with vinyl groups in the polyalkenyl or acetylenic compound. Vinylidene groups also react rapidly when the second group attached to the doubly substituted carbon is relatively small. With larger groups in that position, longer reaction times and increased temperatures, but still below decomposition temperature, are desirable. Terminal acetylenic groups are more reactive than internal acetylenics groups, and ethylenic groups having hydrocarbon groups attached to both the alpha and the beta carbon atoms are still less reactive than the Vinylidene groups, and require longer reaction time even at the more favorable temperature conditions. The time will also vary in accordance with the degree of polymerization required. While the more active reagents can give polymers in even less time, many of the polymeric products of this invention can be produced at moderate temperatures in a matter of 12 to 48 hours. In some cases, such as, with the non-reactive type of ethylenic groups, or when low temperatures, for example as low as 50 C., are used, much longer reaction periods are desirable. In such cases, the reaction is continued until a solid product is obtained.

Polyalkenyl compounds that can be used in the practice of this invention include those having the formula wherein R and Z are as defined above. Typical polyalkenyl compounds that can be used in the practice of this invention, include, but are not limited to, the following: 1,3-butadiene, isoprene, 2,3-dimethyl butadiene, pentadiene-1,3, hexadiene-2,4, octadiene-2,4, hexatriene-l,3,5, 2-phenyl-butadiene, 1,4-pentadiene, hexadiene-l,5, 2,4- dimethyl-pentadiene-l,4, vinyl cyclohexene, l-phenylpentadiene-1,3, divinyl cyclohexane, diallyl, 1,6-heptadiene, 1,8-nonadiene, 2,8-decadiene, 2,9-dimethyl-2,8- decadiene, divinyl cyclopentane, divinyl methyl cyclohexane, diallyl cyclohexane, diallyl cyclopentane, dibutenyl cyclohexane, dipentenyl cyclohexane, allyl cyclohexene, diallyl cyclohexene, divinyl cyclohexane, 1,7-diphenylheptadiene-l,6, 2,7-diphenyl-octadiene-1,7, etc.

Polyalkenyl aryl compounds which can be used in the practice of this invention include: divinyl benzene, trivinyl benzene, divinyl napthalene, trivinyl naphthalene, divinyl diphenyl, trivinyl diphenyl, divinyl toluene, trivinyl toluene, divinyl Xylene, divinyl ethyl benzene, divinyl chlorobenzene, divinyl methylnaphthalene, divinyl ethylnaphthalene, divinyl methyldiphenyl, divinyl ethylidiphenyl, vinyl isopropenyl benzene, vinyl isopropenyl naphthalene, vinyl isopropenyl diphenyl, vinyl isopropenyl toluene, vinyl isobutenyl benzene, vinyl isobutenyl naphthalene, vinyl isobutenyl diphenyl, vinyl allyl benzene, vinyl allyl naphthalene, vinyl allyl diphenyl, vinyl allyl toluene, vinyl allyl methylnaphthalene, diallyl benzene, triallyl benzene, diallyl naphthalene, triallyl naphthalene, diallyl diphenyl, triallyl diphenyl, diallyl toluene, diallyl Xylene, diisopropenyl benzene, diisopropenyl naphthalene, diisopropenyl diphenyl, diisopropenyl toluene, diisopropenyl methyl naphthalene, dimethallyl benzene, dimethallyl naphthalene, dimethallyl diphenyl, bis-(alpha-ethylethenyl)-benzene, bis-(alpha-ethyl-ethenyl) naphthalene, bis-(alpha-ethyl-ethenyl) diphenyl, bis (alpha-vinylethyl) -benzene, bis-( alpha-vinyl-ethyl) -naphthalene, bis- (alpha-vinyl-ethyl)-diphenyl, vinyl (alpha vinyl-ethyl)- benzene, vinyl (alpha-vinyl-ethyl)-naphthalene, vinyl (alpha-vinyl-ethyl)-diphenyl, etc.

Other polyalkenyl aryl compounds that can be used include: dipropenyl benzene, p-propenyl styrene, parapropenyl isopropenyl-benzene, dicrotyl benzene, dicrotyl naphthalene, dicrotyl diphenyl, dicrotyl Xylene, bis-(4- vinyl-n-butyl) benzene, bis (5 isopropenyl-n-hexyl)- benzene, bis-(S-methyl-nonene-6-yl) diphenyl, bis-(ndecen-S-yl) -toluene, di-cyclopentenyl naphthalene, dicycloheXenyl-benzene, etc.

Typical acetylenic and allenic compounds that can be used in the practice of this invention include, but are not limited to the following: acetylene, methyl acetylene, ethyl acetylene, propyl acetylene, amyl acetylene, vinyl acetylene, diacetylene (butediyne), dipropargyl (hexadiyne-l,5), heXadiyne-2,4, allene, butadiene-LZ, 4-methylpentadiene-1,2, tetramethyl allene, phenyl acetylene, phenylene diacetylene, para-vinyl phenyl acetylene, naphthyl acetaylene, cyclohexyl acetylene, cyclopentyl acetylene, naphthylene diacetylene, cyclohexylene diacetylene, dipropargyl benzene, dipropargyl naphthalene, dipropargyl cyclohexane, p-propargyl styrene, etc.

Compositions of this invention are also prepared from polymeric hydrocarbon materials containing a plurality of unsaturated groups therein, such as ethylenic and acetylenic groups, by reaction with the metal compounds. The polymeric materials used in the preparation of these compositions have a molecular weight of at least about 500, advantageously above 1,000, and have an average of at least four unsaturated groups per polymer molecule, advantageously more than ten such groups per polymer molecule.

The polymeric starting materials include polymers of polyunsaturated hydrocarbon monomers in which sub stantially only one of the unsaturated groups has been reacted in forming the polymer, and a substantial amount of the other unsaturated group or groups remains unreacted.

In polymers having a plurality of repeating units therein in which there is an unsaturated hydrocarbon group, e.'g., an ethylenic or acetylenic group, the unsaturated repeating unit of the starting polymer can be represented as Y" and the resultant repeating unit after the metal hydride addition as .'l BeX wherein X represents R or another Y group.

The reaction can be represented at least initially as follows:

]3eR]n For example, when a 1,2-butadiene polymer is reacted with BeR or Bel-IR to replace only one R group or only the hydrogen in the hydride, the reaction can be represented initially at least as:

When the R .group is also replaced the resultant repeating unit structure can be represented by Thus when the 1,2-butadiene polymer shown above is further reacted to displace the second R group of the BeR the polymer will have a plurality of repeating units of the formula CH-CH2- In such polymeric products the portion of the polymers consisting of the hydrocarbon portion having a plurality of the Y repeating units can be represented as Y, with BeR or BeY groups attached thereto. Thus, these polymeric products also fit the generic formula R[BeY] BeR as described above. Typical examples of polyunsaturated hydrocarbon monomers that can he used in the preparation of these polymeric starting materials are the polyunsaturated compounds listed above for use as such in the practice of this invention.

Polymers having pendant groups, such as vinyl or vinylidene groups or terminal acetylenic groups therein, such as in 1,2-polybutadiene types of polymers, are preferred in the practice of this invention, since they react more easily with the metal compounds, but it is also possible to use polymers having ethylenic groups other than vinyl and vinylidene groups, and acetylenic groups other than terminal ones. In such cases, the reaction with the metal compound can be completed satisfactorily by the application of higher temperatures, or longer reaction periods than are generally required with the vinyl, vinylidene, or terminal acetylenic groups. Methods of polymer preparation which favor the production of pendant types of unsaturated groups and methods of determining relative percentages of such groups are Well known in the art. Typical unsaturated polymeric materials include uncured polymers and copolymers of butadiene, isoprene, divinyl benzene, 2,3- dim-ethyl butadiene, uncured natural rubber, ethyleneacetylene copolymers, etc., as listed above for the formula R C-CRZCR=CR Polymers having pendant vinyl, vinylidene, or terminal acetylenic groups, particularly useful in the practice of this invention, are those having repeating units, such as the followin typical types:

Typical polymeric starting materials having ethylenic or acetylenic groups not of the terminal type include those having repeating units of the foilowing types:

(IDH3 5H5 CH CH2 H OH; on

It is generally desirable to use proportions of the reactants in accordance with the properties desired in the polymer products. For example, if low molecular weight products are desired, molar proportions of the acetylenic or ethylenic compound in excess of the theoretical proportions favor this. Where high proportions of the metal are desired, this is favored by use of excess metal compound, and also by the use of compounds having a greater number of unsaturated groups .therein. High proportions of metal in the product are also favored by the use of low molecular weight :acetyleni'c and ethylenic compounds.

The addition reactions of the invention are promoted by organic ethers, such as for example, diethyl ether, diisopr-opyl ether, tetrahydrofurane, diglyme, vinyl ethyl ether, vinyl butyl ether, vinyl propyl ether, vinyl amyl ether, vinyl cyclohexyl ether, vinyl phenyl ether, vinyl tolyl ether, isopropenyl ethyl ether, isopropenyl isopropyl ether, isopropenyl butyl ether, isopropenyl phenyl ether, isopropenyl amyl ether, isobutenyl ethyl ether, all yl methyl ether, allyl ethyl ether, allyl propyl ether, butenyl ethyl ether, butenyl propyl ether, pentenyl amyl ether, vinyl cyclohexyl ether, vinyl cyclopentyl ether, para-vinyl anisole, allyl benzyl ether, vinyl benzyl ether, vinyl phenethyl ether, isopropenyl phenethyl ether, etc., as well as corresponding dialkenyl ethers, such as divinyl ether, diallyl ether, etc. Such unsaturated ethers as indicated above can be added directly to the reaction mixture to serve as modifiers as well as catalysts. They can also be reacted with the metal compounds and then added.

Typical m ono-alkenyl modifiers that can be used in the practice of this invention include, but are not limited to, the following: ethylene, propylene, butene-l, butene-Z, hexene-l, hexene-Z, t-butyl-ethylene, 2,4,4-trimethyl-1-per1- tene, 2,4,4-trimethyl-pentene-2, cyclopentene, cyclohexene, styrene, l,l-diphenyl ethylene, vinyl cyclohexane, alpha methyl-styrene, vinyl naphthalene, beta-methyl styrene, allyl benzene, allyl cyclohexane, decene-l, dec-ene-Z, decene-3, decene-4, decene-S, dodecene-l, dodecene-2, tetradecene-l, hexadecene-l, cycloheptene, etc.

Various methods of practicing the invention are illustrated by the following examples. These examples are intended merely to illustrate the invention and not in any sense to limit the manner in which the invention can be practiced. The parts and percentages recited therein, and also in the specification, unless specifically provided otherwise, refer to parts by weight and percentages by weight. Unless indicated otherwise, the terms polymer and polymeric are intended to include copolymers and copolymeric. Molecular weights given herein are Staudinger molecular Weights.

EXAMPLE I A mixture of 67 parts of diethyl beryllium dissolved in 100 parts of hexane is added to 130 parts of divinyl benzene, and is heated in an atmosphere of nitrogen to CPI;

boil off the hexane. After the hexane is thus removed, the temperature is raised and maintained at C. Ethylene is gradually evolved from the reaction mixture. After heating for 72 hours, the reaction mixture is cooled and a solid product is obtained. This is ground with an equal weight of ammonium perchlorate. The resultant mixture burns vigorously when ignited and when tested for propellant thrust shows excellent thrust properties.

EXAMPLES II The procedure of Example I is repeated except that in place of the divinyl benzene, a mixture of 104 parts of divinyl benzene and 30 parts of trivinyl benzene is used. In this case, an infusible product is obtained, which, after grinding with an equal weight of ammonium perchlorate, shows vigorous burning properties when ignited, and excellent thrust properties.

EXAMPLE III The procedure of Example I is repeated, using in place of the diethyl beryllium, a mixture of 44 parts diethyl beryllium and 38 parts of triethyl aluminum. An infusible product is obtained which, when ground with an equal weight of ammonium perchlorate, burns vigorously upon ignition and shows excellent thrust properties.

EXAMPLE IV The procedure of Example I is repeated, using in place of the divinyl bezen-e an equivalent weight of diallyl, omitting the hexane. and sealing the mixture und'en vacuum in a glass tube. The resultant solid product shows similar burning and thrust properties as for the product of Example 1.

EXAMPLE V The procedure of Example IV is repeated with similar results, using 39 parts of ethyl beryllium hydride and 68 parts of isoprene.

EXAMPLE V I The following procedure is followed a number of times, using in each case a different mixture as indicated in Table I below. The number appearing before a particular compound in this take and in subsequent tables, indicates the number of parts by weight of that compound used. In each case the mixture is maintained under an atmosphere of nitrogen, and the temperature is raised gradually over a period of several hours and then maintrained at l20-l30 C. for a period of about '72 hours. In each case the resultant solid product is processed as in Example I and upon testing exhibits excellent burning and thrust properties.

TABLE I 6% Dip prl be yllium. 23!) Uivinyl toiucnc. 46TH yl horo 1 Eth, at

Hip enyl bcrylhum. 2S0 Diviuyl diplrcnyl.

1ft) 'lripheux imiiuiin. 22o l)1styryl beryllium.

2G0 Dicycloluixyl beryllium.

160 Dibutyl beryllium.

2.30 D i-(Ii-phenyl-propyl) I "l naplitlutlene. beryllium.

yloxy propane.

EXAMPLE V II perature is gradually raised to -130 C. for approximately 72 hours. The products are processed as in Ex- I i ample I, and each product exhibits excellent burning and thrust properties.

TABLE II 39 Ethyl beryllium hydride. 53 Propyl beryllium hydride.

87 Phenyl beryllium hydride.

93 Cyclohexyl beryllium hydride.

EXAMPLE VIII Various mixtures indicated in Table III below are treated according to the following procedure. The mixture is heated in 150 parts of hexane, in each case, under a blanket of nitrogen under refiux for two hours. Then the hexane is slowly distilled off and in accordance with the corresponding increase in reflux temperature the temperature is gradually increased to 7080 C. and maintained at that temperature for approximately five hours. Then, the temperature is gradually increased to l13-0 C. for a period of 72 hours. A solid product is obtained in each case and upon processing as in Example I, each product exhibits excellent burning and thrust properties.

TABLE III 66 Cyclopentadiene. 100 Vinyl cyelohexene. 100 Trivinyl benzenev 110 Octadienc-l, 7.

40 Oetatriene-l, 3, 7. 100 Diallyl.

100 Divinyl benzene. Tris(beta-ethoxy-ethyl)-borane.

EXAMPLE Ia A mixture of 12 parts of di-secondary-butyl-beryllium, 1 part dioxane, and 50 parts of heptane is heated in an atmosphere of nitrogen at 50 C. Pure acetylene is bubbled into the solution at such a rate that the temperature does not rise above 55 C. When approximately 3 grams of acetylene has been absorbed, the acetylene supply is shut off and the temperature is maintained for an additional two hours. Then the temperature is raised gradually to distill off the heptane, following which the temperature is taken to 120 C. for a period of hours. The resultant solid product is ground with an equal weight of ammonium perchlorate. This mixture, when ignited and tested, according to known tests for propellant thrust, shows excellent thrust properties.

EXAMPLE 11a The procedure of Examples la is repeated, using 7 parts of diethyl beryllium in place dibutyl beryllium, and 4.5 parts of methyl acetylene in place of the aoetylene. In three different tests, 4 parts of the resultant polymer are ground individually with 6 parts of ammonium perchlorate, lithiLLn1 perchlorate, and potassium perchlorate, respectively. In each case, the mixture when ignited burns very rapidly with an intense White flame, and upon testing for thrust properties shows excellent thrust.

EXAMPLE IIIa The procedure of Example 11a is repeated, except that allene is used in place of the methyl acetylene. Similar results are obtain d.

The same procedure used with an equivalent weight of propyl acetylene also gives similar results.

EXAMPLE IVa The following procedure is repeated eight times, using in each case 12 parts of di-isobutyl beryllium and with each experiment a progressively smaller amount of phenyl acetylene, as follows: 45, 33, 22, 11, 9, 5.5, 3.3, and 2 parts, respectively. In each case, the mixture of di-butyl beryllium and phenyl acetylene is prepared at room temperature under an atmosphere of nitrogen, and then the temperatureis raised gradually to C. and maintained there under the nitrogen atmosphere until the reaction mixture forms a solid cake and no more butene is released from the reaction. The product is ground with an equal weight of ammonium perchlorate. This mixture when ignited and tested, according to known tests for propellant thrust, shows excellent thrust properties.

EXAMPLE Va The procedure of Example In is repeated, using 10 parts of dipropyl beryllium and 4.5 parts of vinyl acetylene. An insoluble product is produced which shows excellent burnin and thrust properties.

EXAMPLE VIa To a solution of 25 parts of di-isobutyl beryllium in parts of heptane, covered by a blanket of nitrogen, is added 13 parts of phenylene diacetylene. The resultant mixture is heated under an atmosphere of nitrogen and the temperature is raised gradually to remove the heptane by distillation. Then the temperature is maintained in the range of 10-0l20 C. for 48 hours. The resultant solid product is washed with heptane, and then ground with an equal weight of ammonium perchlorate. The resultant mixture, when ignited and tested, shows excellent burning and thrust properties.

The above procedure is repeated, using in one case cyclohexylene diacetylene, and in another case naphthylene diacetylene in amounts equivalent to and in place of the phenylene diacetylene used in the above procedure. 11; each case results are obtained similar to those indicated a ove.

EXAMPLE VIIa The procedure of Example VIa is repeated, using 35 parts of distyryl beryllium in place of the di-isobutyl beryllium. The resultant solid product, when ground with an equal weight of ammonium perchlorate, shows excellent ignition and thrust properties.

EXAMPLE VIIIa The following procedure is repeated a number of times, using in each case a different mixture selected from those indicated in the table below. The number appearing in the table before a particular compound indicates the number of parts by weight of that compound used. In each case the iacetylenic or allenic compound, together with any solvent or modifier, is maintained under an atmosphere of nitrogen at a temperature of 5055 C. In the case of vinyl acetylene, it is fed into the heptane solvent at such a rate that it is present in molecular excess to the amount of beryllium dihydride present. Any acetylenic 0r :allenic compound lost from the system through volatillzation is caught in a. low temperature trap and returned to the system. A solution of 20 parts of beryl l1urn hydricle in 100 parts of other is dropped into the reaction mixture While under a blanket of nitrogen, at such a rate that no more than a 5 degree rise in temperature occurs. When the temperature rises :above 60 C., the beryllium hydride solution supply is cut ofi? or reduced until the temperature has subsided to the desired range. During this addition period, the ether is allowed to vaporize from the reaction mass and is recovered by condensation at a point before the low temperature trap mentioned above. After all the solution has been added, the heating is continued for a period of two hours, after which the temperature is raised to the solvent reflux tem perature for a period of ten hours, and where no solvent is used a temperature of approximately 80 C. is maintained for that period. Then the solvent, Where present, is distilled off. The resultant product in each case, upon testing as in Example Ia, shows excellent burning and thrust properties.

TABLE Acctylenic or Allenic Compound Modifier Solvent 100 Plicnyl acetylene 90 Phenyl acetylene I l 20 Phcnylene diacttylene i Heptyle 90 Phony] acet le D0. 1C Cyclohe Z Heptnnc. 30 Vinyl ac 2 H Qyclohcxsmc. 75 Phenvlene diacetylen lot) lieptnnz w 9 l0 lctrahydrofurnnc. 80 llexadune-l, no Hemflm 100 Amyl acetylene r. 100 lleptant.

120 p-Vinyloxy-phenyl acetylene" 100 Crelohcxane.

EXAMPLE IXa A mixture of 7 parts of diethyl beryllium and l0 parts of phenyl acetylene is heated under a nitrogen atmcsphere at 70 C. for 10 hours. The mixture is then cooled to room temperature and 10 parts of styrene and 36 parts of finely ground ammonium perchlorate are added. The mixture is milled to uniformity and then press-cast in the form of a rod and heated at 6070 C. for 12 hours. A solid, infusible product is obtained which shows excellent thrust properties.

EXAMPLE Xa A mixture of 33 parts of distyryl beryllium, parts of amyl acetylene, and 2 parts of para-allyloxyphenyl "acetylene is heated at 70 C. in a sealed container for a period of 48 hours. The resultant solid product shows excellent burning and thrust properties.

The above procedure is repeated using 40 parts of phenylacetylene in place of the amylacetylene, and also 80 parts of ammonium nitrate, to produce a solid propellant fuel of excellent thrust.

EXAMPLE XIa A mixture of 11 parts of diallyl beryllium and 7 parts of triethyl aluminum is heated under an atmosphere of methane for 15 hours at 90 C. An insoluble, intusible product is obtained. This polymer is believed to have, at least in part, repeating units of the foliowing structure:

By using equivalent amounts of diethyl magnesium and triethyl borane, respectively, in place of the triallyl aluminum, and in each case repeating the preceding procedure, two solid products are obtained which are believcd to have, at least in part, repeating units of the following structure:

respectively.

EXAMPLE XIIa Ten parts of the polymer of Example In is mixed uniformly with 40 parts of finely divided ammonium perchlorate in a solution of 9 parts of styrene, one part of a 50/50 commercial divinyl benzene-ethyl styrene mixture, and 0.1 part of benzoyl peroxide. The mixture is cast and maintained at 70 C. for 12 hours. An insoluble, infusible polymer product is obtained, which shows excellent thrust properties.

EXAMPLE XIIIa A mixture of 10 parts of beryllium hydride, 0.1 part tetrahydrofurane, and 100 parts of heptane is prepared and maintained under an atmosphere of nitrogen at -l0 C. Pure acetylene is bubbled into the solution at such a rate that the temperature is raised only very slowly to no higher than 50-55 C. Volatile reactants escaping from the system are caught in a cold trap and returned to the reaction mixture. When approximately 3 grams of acetylene has been absorbed, the acetylene supply is shut off and the temperature is maintained at 5055..C.

The polymerization described herein can be suspended at an early stage to give low-melting, solid polymers, or in some cases viscous oils, which can be stored as such and the polymerization reaction continued at a subsequent time. In fact, the reaction can be suspended when the product comprises substantially a monomeric product, such as, for example, that derived from a beryllium hydride compound and allene, namely:

RB ECH CH CH nucn crr cum and the polymerization completed later by the application of heat or the addition of beryllium hydride compounds or other reagents, catalysts, modifiers, etc.

EXAMPLE I!) A solution of 12 parts of di-secondary-butyl beryllium, 15 parts of solid, soluble polymer of divinyl benzene, and 0.2 part of diethyl ether in parts of toluene, is heated in an atmosphere of nitrogen at 50 C. for one hour. Then the temperature is raised to 70 C. for two hours, and thereafter refluxed for five hours. The toluene is then distilled oft and the reaction mixture heated at C. for 24 hours. The solid product is washed with heptane to extract traces of unconverted dibutyl beryllium. The washed product is more stable in air than the ordinary organo-berylliums which oxidze and burn in air. The resultant product is ground with an equal weight of ammonium perchlorate. The resultant mixture, when ignited, burns very rapidly with an intense white flame, and when tested according to known tests for propellant thrust, shows excellent thrust properties.

EXAMPLE 11b The procedure of Example lb is repeated, using 15 parts of diethyl beryllium, in place of the dibutyl beryllium, and 0.2 part of divinyl ether. In three different tests, 2 parts of the resultant polymer are ground individually with 8 parts of ammonium perchlorate, lithium perchlorate, and potassium perchlorate, respectively. In each case, the mixture, when ignited, burns very rapidly with an intense white flame, and upon testing for thrust properties, shows excellent thrust.

15 EXAMPLE IIIb The procedure of Example Ib is repeated, except that in place of the divinyl benzene polymer, there is used 6 parts of a solid, soluble polymeric butadiene, having apl 3 an atmosphere of nitrogen at a temperature of 5055 C. A solution of 11 parts of beryllium hydride and 100 parts of ether is dropped into the reaction mixture covered by a blanket of nitrogen, at such a rate that no more than 5 a. 5 percent rise in temperature occurs. When the tem- $$i ig g ggizgi i lz-polybutadlene structure' perature rises above 60 C. the beryllium hydride solution supply is cut off or reduced until the temperature has sub- EXAMPLE 1V1) sided to the desired range. During this addition period, The procedure of Example 15 is repeated, except that the ether is allowed to vaporize from the reaction mass. in place of the divinyl benzene polymer, there is used a 10 *fter an the e has been added the beefing solid, soluble butadiene polymer having approximately 10 tmued a Period of two hours after Whleh the percent of 1,2-polybutadiene structure, and the final heat- Pereture 1S reused to the solvent reflux F P F for a ing is conducted for 60 hours instead of 24. The product e of hours' The, the seh'ent jdlstlued Off and Shows good burning and thrust properties heating continued at 90 C. for an additional hours. 15 The resultant product in each case shows excellent burning EXAMPLE Vb and thrust properties. The following procedure is repeated eight times, using TABLE I in each case 12 parts of di-isobutyl beryllium, and with each experiment a progressively smaller amount of a solid, Polyunsaturated Polymer of: Modifier or Catalyst; soluble polymeric butadiene having approximately 60 percent 1,2-polybutadiene structure, as follows: 24, 18, 1003-Viuylcyelohexeue 5Diallyl ether. 12 6, 45 3 2 and 15 parts respsctively. In each Case fiOrfiggyleue acetylene copol mer (75-25 mole 1 Divinyl ether. the beryllium compound and the polymer are dissolved in 70 rsopr'ene 5 Allyl propyl ether. 100 parts of benzene and heated under an atmosphere of gg g gghgfigf 10 Styrene nitrogen at 50 C. for a period of two hours, and then 120 Divii lyl bentite'aimy'rart; 551555115? refluxed for a period of ten hours. Then the benzene is g g -g 1g f 2 distilled off and the reaction mixture lS heated under 80 Uucureduaturalrubber 10 Divinyl ether. nitrogen atmosphere at 100l30' C. for hours. The product in each case is treated as in Example lb and shows excellent burning thrust properties. 30 EXAMPLE XII) Six experiments are performed, using in each case a EXAMPLE VIb different solution of the beryllium compound, soluble The procedure of Example Ib is repeated, using 9 parts polymer, and catalyst or modifier, dissolved in 150 parts of dipropyl beryllium, 14 parts of solid, soluble polymer of benzene, selected from Table III) below, and heated of para-allyl styrene, and 0.3 parts of di-(allyloxypropyl) 30 under an atmosphere of nitrogen at 50 C. for one hour, beryllium. Similar results are obtained. then 70 C. for two hours, then refluxed for five hours,

following which the benzene is distilled off and the re- EXAMPLE action mixture heated at 100 C. for 48 hours. Excel- The procedure of Example VIb is repeated, using 11 4O lent burning and thrust properties are exhibited by each parts of distyryl beryllium and 15 parts of a solid, soluble product when tested according to Example Ib.

TABLE III) Beryllium Polymer of: Catalyst or Modifier Ethyl beryllium hydride 55 Butadiene 5 Vinyl ethyl ether. 55 Butyl beryllium hydride 70 Butadieue-styrene copolyrner (7525 weight ratio). 2 Tetrahydrofuran. 115 Styryl beryllium hydride r 55 Ethylene-acetylene copolymer (7525 mole ratio). 5 Divinyl ether. 70 Propyl beryllium hydride 265 Divinyl benzene-ethyl styrene eopolymer (5050 Weight ratio). 2 Diethyl ether. 100 Cyclohexyl beryllium hydride 150 p-Allyloxystyrene 10 Styrene. 90 Phenyl beryllium hydride 50 Vinyl acetylene- 2 Diethyl ether.

polymer of para-isopropenylstyrene. The product shows EXAMPLE XIIb excellent bummg and thrust propertles A solid, soluble polymer of divinyl benzenes (130 EXAMPLE VIIIb parts) is mixed under a nitrogen atmosphere with 45 The procedure of Example VIII) is repeated, using 15 parts dipropyl 11mm on a Btmbury f The parts of a solid, soluble polymer of para-vinyloxy-styrene, resultant 1s lheated under mtrogen at 80 in place of the para-isop-ropenyl-styrene, and omitting the 72 hours 6 resu tam product when ested accordmg di (auyloxypropyl) beryllium The product Shows toO Extample I, shows excellent burning and thrust cellent burning and thrust properties. pr per EXAMPLE XIHb EXAMPLE IXb The procedure of Example XIIb is repeated using 60 The Procfidufe 0f EXample V1111 is repeated, using 16 parts of dipropyl beryllium and 30 parts of styrene, in Parts Of a Solid, Soluble Polymer of p y yy place of the 45 parts of dipropyl beryllium of Example in place of the vinyloxy-styrene. The product shows simi- XIIb, Si il results are Obtained lar burning and thrust properties.

EXAMPLE XIVb EXAMPLE Xb The procedure of Example XIII; is repeated with simi- The following Pr0C6d11fe is rfipeated eight times, using lar results, using 120 parts of dibutyl beryllium in place in eiagh case a diflerenlt merittgre of fiolubledpolyrgrer artild of h di b l i mo 1 er or cata yst, se ect rom t ose in icate in t e table below. The number appearing in the table before EXAMPLE Xvb a particular compound indicates the number of parts by The procedure of Example XIII) is repeated using in weight of that compound used. In each case the polyplace of the dipropyl beryllium, 200 parts of distyryl unsaturated polymer dissolved in parts of benzene, p beryllium, and 100 parts of tributenyl aluminum. An together with any catalyst or modifier, is maintained under insoluble, infusible product is obtained, which has ex- 17 cellent burning and thrust properties. both beryllium and aluminum in molecules.

By using equivalent amounts of dibutenyl magnesium and tributenyl boron, respectively, in place of the tributenyl aluminum, and in each case repeating the preceding procedure, two solid products are obtained having similar burning and thrust properties. These polymeric products have beryllium and magnesium in the polymeric molecules of one, and beryllium and boron in the polymeric molecules of the other product.

EXAMPLE XVIb Ten parts of the polymer of Example 112 is mixed uniformly with 40 parts of finely divided ammonium perchlorate in a solution of 9 parts of styrene, one part of a 50-50 commercial divinyl benzene-ethyl styrene mixture, and 0.1 part of benzoyl peroxide. The mixture is cast and maintained at 70 C. for 12 hours. An insoluble, infusible polymer product is obtained, which shows excellent burning and thrust properties.

EXAMPLE XVIII) The procedure of Example XIIb is repeated using 125 parts of dibutenyl .beryllium in place of the dipropyl beryllium. The product shows excellent burning and thrust properties when tested as in Example 1b.

Typical unsaturated compounds that can be used for preparing polymers and copolymers having unsaturation therein suitable for preparing the compositions of this invention include, but are not limited to, the following:

The polymerization described herein can be suspended at an early stage to give low-melting, solid polymers, or in some cases viscous oils, which can be stored as such and the polymerization reaction continued at a subsequent time. In fact, the reaction can be suspended when the product comprises substantially a monomeric product, such as, for example, that derived from a beryllium hydride compound and butadiene, namely:'

This product has the polymeric Be(CH CH C 2) 2 and the polymerization completed later by the application of heat or the addition of beryllium hydride compounds or other reagents, catalysts, modifiers, etc.

Various modifiers can be added to the compositions of this invention after the polymerization is completed, and in cases where the modifiers are non-reactive with the .beryllium hydride compounds, can be added prior I to the initiation of the polymerization, or at some intermediate stage. Hydrocarbon materials, such as various hydrocarbon resins, e.g. polystyrene, polyethylene, polypropylene, polybutenes, parafiins, etc., can be added at any time. Certain other resins that might influence the reaction, or be reduced or reacted upon by the beryllium hydride compound, such as those containing ester, amide, or other functional groups, can be added after the polymers are formed. However, if sufiicient beryllium hydride compound is added to compensate for that used in such side reactions, such resins can often be added before or during the reaction. Typical resins include, polyethers, such as polymeric vinyl ethyl ether, polymeric vinyl butyl ether, etc., polyesters, such as polyvinyl acetate, polyvinyl propionate, polyvinyl butyrate, polymethyl methacrylate, polymethyl acrylate, etc., polyvinyl acetal, polyvinyl butyral, etc., polyacrylonitrile, polyamides, such as nylon and polymeric caprolactam, etc.

Various other polyunsaturated compounds, in addition to those indicated above, can also be added either before initiation of the polymerization, or at an intermediate stage, or at the completion of the polymerization reaction, to modify the properties of the products. Such polyunsaturated compounds include: polyunsaturated ethers, and

18 various alkenyl derivatives of boron, magnesium, and aluminum.

Typical examples of such polyunsaturated compounds include, but are not restricted to. the following: divinyl other, diallyl ether, vinyl aliyl ether, propenyl vinyl ether, propenyl allyl ether, divinyl ether of resorcinol, divinyl ether of ethylene glycol, dilsopropenyl ether, isopropenyl vinyl ether, isopropenyl allyl ether, isopropenyl butenyl ether, isopropenyl isoamylene ether, dialiyl ether of resorcinol, diisobutenyl ether of hydroquinone, para-vinyloxy styrene, para allyloxy styrene, triallyloxy benzene, tripropenyioxy benzene, etc., triallyl borane, tetra-allyl diborane, tributenyl borane, tributenyl diborane, dibute-nyl magnesium, triallyl aluminum, dibutenyl aluminum, etc.

In addition to the polyalkenyl type of boron, magnesium, and aluminum compounds indicated above, it is desirable in some cases to add monoalkenyl derivatives of such metals and to continue replacement of the remaining hydrogen or saturated hydrocarbon groups on the metal by means of the polyalkenyl compounds, or by such compounds which have already partially reacted with beryllium hydride compounds. By these techniques, both beryllium and other metals can be incorporated in polymeric materials.

For many purposes, such as fuel, it is desirable to have a high concentration of the beryllium polymeric units present in the compositions. In such cases, the modifiers are used in minor amounts. However, in certain cases, it may be desirable to usethe beryllium compositions to modify or fortify the properties of other materials, in which case the beryllium derivatives are used in minor amounts.

As indicated above, the beryllium polymers of this invention are particularly useful as solid fuels. They can be used as the main fuel component, or can beadded to various types of other fuels to fortify or supplement such fuels. For example, they can be used as additives to gasoline and other motor fuels, to kerosene and other ma terials used for turbojet engines and jet engines, and can be added to liquid and solid propellant fuels used for rockets, missiles, etc. However, these polymeric compositions are particularly useful as the main fuel component in solid propellant fuels for rockets and related devices. In such latter cases, it is advantageous to convert the fuel to an infusible form. If modifiers, or auxiliary agents, are to be added, this can be effected before conversion to infusibility. Depending on the particular manner in which the fuel is to be used, it can be in solution, powder, rod, cylinder, or whatever other shape is convenient.

While such products should be made and stored under inert atmospheres, it is surprising that considerable amounts of oxidizing agents can be incorporated into these polymeric compositions and they can be stored in inert atmospheres without danger of premature ignition or explosion. The materials can simply be mixed in finely divided form, or where desired the oxidizing agent can be incorporated into a solid mass of the polymer. Moreover, after the desired amount of oxidizing agent has been incorporated into the polymeric composition, it can be converted to an infusible form by various means, including the addition of aluminum or boron hydrides and hydrocarbon-substituted hydrides, or by the addition of hydrocarbons and ether compounds having three or more ethylenic groups therein, together with theapplication of heat or catalysts to effect crosslinlting through the trivalent metals or through the ethylenic groups, or by any other means of crosslinking.

Oxidizing agents which can be incorporated in the resin for the ultimate purpose of supporting combustion of the the resin and which can be incorporated in accordance with safety conditions determined by their reactivity, include: the solid and liquid perchloryl aryl compounds of the formula Ar-ClO such as perchloryl benzene, perchloryl toluene, etc., various perchlorates, nitrates, oxides,

persulfates, and perborates of metals and ammonia, such as ammonium perchlorate, potassium perchlorate, sodium perchlorate, ammonium nitrate, potassium nitrate, sodium nitrate, potassium permanganate, potassium chlorate, manganese dioxide, potassium iodate, potassium dichromate, chloric acid, perchloric acid, ammonium persulfate, ammonium dichromate, ammonium iodate, aluminum nitrate, barium chlorate, barium perchlorate, barium permanganate, lithium perchlorate, lithium dichromate, lithium permanganate, etc.

Some of these oxidizing agents are not self-sustaining oxidizing agents, and can be used when free oxygen, or compositions such as perchloryl fluoride, highly concentrated hydrogen peroxide, etc., which generate oxygen in situ, are passed in surface contact With the fuel. The liquid oxidizing agents can be incorporated with precautions to assure uniform distribution through the polymer mass and to avoid ignition or explosive conditions during preparation and use of the fuel. It is desirable that the products from reaction of the oxidizing agent and the resin are gaseous in their normal state so that the energy developed in the system will not be robbed of energy to convert them to the gaseous state.

It is generally desirable that the fuel be molded in the shape in which it is ultimately to be used before the composition is converted to an infusible state. In fact, the fuel can even be cast or molded as one entire unit which will comprise the entire fuel load for one rocket and can be substantially as long as the rocket if desired. Therefore, the size is limited only by the size of the rocket in which it is to be used.

it is possible to make the fuel in other shapes than in dicated above and have the fuel machined to give the desired shape. For example, cylindrical shapes are generally desirable with an opening running through the cylinder along its linear axis. If desired, there can be a plurality of such openings running through the length of the mass so that more than one oxidizing stream can function simultaneously. However, various other shapes can be used, such as blocks having rectangular or square cross sections with one or more openings running along the linear axis of the block.

While the aforementioned shapes are preferred, it is also possible to use smaller units or shapes made by the practice of this invention, and then to assemble them in a space or container advantageously in such a manner that one or more open linear paths are left through the assembled mass so that the oxidizing gas and/or the combustion gases can be passed therethrough. For example, the fuel can be in the shape of discs with an opening in the center, or in half or quarter discs, or even with rectangular, square, or various other cross-sections so that upon assembly, one or more openings for the oxidizing gas are formed through the assembled mass. A cylindrical mass can be made of a number of concentric cylinders for which the outer diameter of one is slightly less than the diameter of the inside linear opening of another so that the assembled cylindrical mass actually comprises a number of cylindrical sleeves which fit over one another. The axial opening of the one having the smallest diameter would be the linear axis opening of the assembled mass.

In addition to the foregoing, the resin-oxidizing agent composition can be made in various other shapes, depending on the manner in which it is ultimately to be used. As a further example, it can be shaped as a solid rod, in which case the burning surface will be the outer surface of the rod or cylinder. The outer surface of the rod can be ignited and if a supplementary oxidizing fluid is used, this can be directed against such outer surface of the rod. If desired, the rod can be advanced through an opening in accordance with the desired rate at which the surface is to be exposed to a supplementary oxidizing fluid. The composition can also be shaped in the form of granules, pellets, etc., where it is desired to modify the surface area that is to be exposed for combustion. Such granules can be used as such, or can be adhered to metal surfaces in accordance with the present known art in the use of solid propellant fuel in granular form.

When the oxidizing agent to be added is a solid, it is desirably in fine particle size so as to permit substantially uniform distribution throughout the mass. The oxidizing composition which is to be passed in surface contact with the fuel is of the type generally used presently, such as pure or highly concentrated oxygen. The upper limit in the amount of oxidizing agent to be used is determined by the concentration that can safely be used under the conditions ultimately existing in the fuel zone of the rocket, or by that excess over the stoichiometric amount required for complete combustion of the fuel, whichever limit is reached first. Obviously, the safety limit will vary according to the type of auxiliary oxidizing agent used. The type of fuel base material used together with its heat capacity and heat transmission properties, the temperature which will exist in the preparation and use of the fuel, etc.

Since the fuel composition of this invention can be used according to various methods, varying from the use of a substantial amount of supplemental oxidizing fluid to that in which the combustion is self-sustained by the oxidizing compound contained in the fuel, the minimum amount of such oxidizing agent contained in the fuel will depend on the manner in which the fuel is to be used. When the combustion is to be maintained partly by an oxidizing agent in the fuel and partly by the oxidizing agent pumped through the opening, then obviously the supplemental effect of one agent toward the other will depend on the particular material being used as the oxidizing agent in the fuel and on the particular oxidizing fluid being fed through the opening.

Moreover, in each case the relative amounts cannot be determined on a weight basis but must be determined on the basis of the amount of oxygen available in the particular oxidizing agent used to support the combustion. This depends on the oxygen content of the oxidizing agent and the percent of that oxygen that is liberated for oxidizing purposes upon decomposition of the oxidizing agent. Furthermore, this depends somewhat on the efiiciency with which it is desired to consume the fuel. For example, it might be desirable to have a consider-able excess of oxidizing agent so as to consume the fuel more completely, even though it might mean an inefficient use of the oxidizing agent. Again, if it is permissible to use the fuel with a low efficiency for use of B.t.u. content, then it may be desirable to use a smaller amount of oxidizing agent.

The amount of oxidizing agent imbedded in the fuel itself can be further decreased when a supplemental oxidizing fluid is being pumped into contact with the fuel. Obviously, therefore, the proportion of oxidizing agent imbedded in the fuel base material can vary from 5 percent to approximately 95 percent depending on the various factors involved, such as the efficiency desired, the method and convenience of operation, and the materials being used. Generally, when an oxidizing agent is imbedded in the base material, it is advantageous to use from about 5 percent to 95 percent, preferably about 20 percent to about 75 percent based on the combined weight of oxidizing agent, base material, and any crosslinking modifier that is used.

When an oxidizing agent is used in the fuel base material of the type and in the amount that will be self-sustaining in the combustion of the fuel base material, there will be no need to use an oxidizing fluid on the surface of the fuel. In such cases, the combustion of the fuel is initiated by igniting it by various means presently used for that pur pose, such as a mixture of hydrazine, or unsymmetrical dimethyl hydrazine, and nitric acid, or by triethyl alumi mum and oxygen, or bya torch, or by an electrical ignition system. When the oxidizing agent is not present in selfsustaining amount, liquid oxygen or an efiicient oxidizing compound such as perchloryl fluoride (PC110 can be pumped into contact with the surface of the fuel to supply the oxygen for combustion. In some cases highly concentrated hydrogen per-oxide, such as 98 percent hydrogen peroxide can be used to supply oxygen for combustion.

When a self-sustaining oxidizing agent is distributed throughout the fuel, the desirable amount can be deter mined by calculating the stoichiometric equivalent required for combustion of the fuel, and adjusting the calculation by subtracting, where less than 100 percent elliciency is satisfactory, or adding, where desired, an excess to compensate for the lack of 100 percent efficiency in the actual combustion. Since the conditions of operation do not permit the time and type of mixing which give 100 percent efficiency, where other factors permit, it is sometimes. desirable to have an excess of oxidizing agent which will give 50 percent, or even as high as 100 percent more than the stoichiometric amount of oxygen. When it is permissible or desirable to sacrifice some of the efiiciency of the Btu. content of the fuel, the stoichiometric amount or even less than that amount of the oxidizing agent can be used, depending on the fuel eificiency desired.

The oxidizing agent and/ or modifier can be introduced or suspended in the solid fuel in any convenient or appropriate manner. The mixture can be effected mechanically as on mixing mills, on a Banbury mixer, any single or double worm extruder, or by rotation of the mold when the material is being cast from a liquid state. When a solid is to be added, the thermoplastic material can desirably be softened by the addition of a softening agent, or, as indicated above, by the modifier itself. Such compounded mixtures can then be extruded, or otherwise shaped into the desired form and then polymerized to infusibility. In some cases, depending on the particle size of the solid oxidizing agent and the amount of void space between particles, the polymer in liquid state, or the monomer from which it is to be prepared, together with a polymerization catalyst of the peroxy or azo type, can be poured into a container holding the solid oxidizing agent and thereby fill the void spaces. Then upon standing at room temperature, or at slightly raised temperatures, the polymer or monomer will be converted to an infusible state with the oxidizing agent embedded therein.

However, whichever method of mixing is used, it is desirable to avoid the generation of heat that will raise the temperature to the ignition point of the oxidizing agent. Therefore, in some cases, it is desirable to precool the materials to be mixed or to provide means to withdraw the heat as it is generated.

While certain features of this invention have been described in detail with respect to various embodiments thereof, it will, of course, be apparent that other modifications can be made within the spirit and scope of this invention, and it is not intended to limit the invention to the exact details shown above except insofar as they are defined in the following claims.

The invention claimed is:

l. A polymeric composition useful as a solid propellant fuel consisting essentially of -95 percent by weight of an oxidizer selected from the class consisting of (1) solid, inorganic oxidizing salts and (2) compounds having the formula ArClO wherein Ar is a mononuclear aromatic hydrocarbon radical, and 955 percent by weight of a polymer having a plurality of repeating units in the polymer molecules thereof of the formula Be-*Y, in which Y is a polyvalent hydrocarbon radical having each of its valencie-s attached to a beryllium atom.

2. A polymeric composition of claim 1 in which said polymer has a plurality of repeating units in the polymer molecules thereof having the formula -'Be--C2H4C H4C2H 3. A polymeric composition of claim 1 in which said polymer has a plurality of repeating units in the polymer molecules thereof having the formula Be-C H 4. A polymeric composition of claim 1 in which said polymer has a plurality of repeating units in the polymer molecules thereof having the formula 5. A polymeric composition of claim 1 in which said polymer has a plurality of repeating units in the polymer molecules thereof having the formula 6. A polymeric composition of claim '1 in whieh said polymer has a plurality of repeating units in the polymer molecules thereof having the formula 7. A polymeric composition of claim 1 in which said polymer has a plurality of repeating units in the polymer molecules thereof having the formula 8. A polymeric composition of claim 1 in which said polymer has a plurality of repeating units in the polymer molecules thereof having the formula 9. A polymeric composition of claim 1 in which said polymer has a plurality of repeating units in the polymer molecules thereof having the formula BeC H.;.

10. A polymeric composition of claim 1 in which said polymer has a plurality of repeating units in the polymer molecules thereof having the formula BeC H 11. A polymeric composition of claim 1 in which said oxidizer is potassium perchlorate.

12. A polymeric composition of claim 1 in which said oxidizer is ammonium perchlorate.

13. A polymeric composition of claim 1 in which said oxidizer is an aryl perchloryl compound.

14. A polymeric composition of claim 1 in which said oxidizer is perchloryl benzene.

15. A polymeric composition of claim 1 in which said oxidizer is lithium perchlorate.

16. A polymeric composition of claim 1 in which said oxidizer is sodium perchlorate.

17. A polymeric composition of claim 1 in which said oxidizer is potassium perchlorate and said polymer has a plurality of repeating units in the polymer molecules thereof having the formula BeC I-I C H C H 18. A polymeric composition of claim 1 in which said oxidizer is potassium perchlorate and said polymer has a plurality of repeating units in the polymer molecules thereof having the formula -BeC -H 19. A polymeric composition of claim 1 in which said oxidizer is potassium perchlorate and said polymer has a plurality of repeating units in the polymer molecules thereof having the formula Be-C4, 7(CH 20. A polymeric composition of claim 1 in which said oxidizer is potassium perchlorate and said polymer has a lurality of repeating units in the polymer molecules thereof having the formula BeC H.

No references cited.

BENJAMIN R. PADGE'IT, Primary Examiner.

ROGER L. CAMPBELL, Examiner. 

1. A POLYMERIC COMPOSITION USEFUL AS A SOLID PROPELLANT FUEL CONSITING ESSENTIALLY FO 5-95 PERCENT BY WEIGHT OF AN OXIDIZER SELECTED FROM THE CLASS CONSISTING OF (1) SOLID, INORGANIC OXIDIZING SALTS AND (2) COMPOUNDS HAVING THE FORMULA ARCIO3, WHEREIN AR IS A MONONUCLEAR AROMATIC HYDROCARBON RADICAL, AND 95-5 PERCENT BY WEIGHT OF A POLYMER HAVING A PLURALITY OF REPEATING UNITS IN THE POLYMER MOLECULES THEREOF OF THE FORMULA -BE-Y-, IN WHICH Y IS A POLYVALENT HYDROCARBON RADICAL HAVING EACH OF ITS VALENCIES ATTACHED TO A BERYLLIUM ATOM. 